The Flight of the Oligarchs (or, “Life on the High Seize”)

In recent days there has been a flurry of activity in European ports seeking to impound super yachts owned by Russian oligarchs pursuant to sanctions for the Russian invasion of Ukraine.

Questions arise as to the legality of seizing these ships while in port or in the territorial sea of a coastal State or on the high seas.

The situation in port is relatively straightforward. Ports form part of the territory of a State over which that State has sovereignty. Any ship in port is subject to the laws of the port State. It follows that if the port State passes a law permitting such seizure, then the seizure can be legally made. The ship owner may wish to challenge the validity of the law and the seizure but if and until the challenge is successful or an injunction is granted, the seizure is valid and effective.

If the ship escapes the port but is still in the territorial sea of a coastal State, that is within 12 nautical miles of the coast, the situation is more complicated. Under the Law of the Sea Convention, the territorial sea forms part of the territory of the coastal State and the coastal State has sovereignty over it. This is subject to the right of any ship in the territorial sea to exercise innocent passage. This right can be lost in a number of situations where passage of the ship is prejudicial to the peace, good order or security of the coastal State. The coastal State has the right to take all measures to prevent passage which is not innocent. Seizing a ship on this basis is not as clear cut as when it is in port but arguably can be done. In this situation any seizure must be done by naval or other government ships.

The situation changes markedly if the ship is on the high seas. Any attempt to seize a ship on the high seas by any State other than the flag State would be highly questionable. In most situations, while a ship is on the high seas the flag State has exclusive jurisdiction over it. Theoretically, the flag State could seize the ship on the high seas pursuant to sanctions, but as it is probable that most of the oligarchs’ ships are flagged in a flag of convenience State this is highly unlikely to happen.

States other than the flag State can exercise jurisdiction over the ship while on the high seas in very limited circumstances. Under the Law of the Sea Convention, the exceptions are essentially that the ship must be engaged in piracy, the slave trade or drug running. Under the Convention for Suppression of Unlawful Acts Against the Safety of Maritime Navigation, 2005, a ship can be seized if it has been involved in an offence against maritime security or is carrying weapons of mass destruction. It is highly unlikely that any of these exceptions would apply.

In summary, provided there is legal authority in a port State to seize the ship while in port, it can do so. It is more problematic, but possible, in the territorial sea. If, however, the ship manages to reach the high seas only the flag State can seize it unless one of the exceptions apply. If the ship can then reach a friendly port, nothing more can be legally done.


Dr Anthony Morrison is Research Fellow. Australian National Centre for Ocean Resources and Security (ANCORS), University of Wollongong, and StevensVuaran Lawyers’ maritime law consultant.

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March 4
Maritime Law